(1) Field of the Invention
This invention relates to a polyamide composition. More particularly, it relates to a polyamide composition having an enhanced adhesion to coatings formed from various paints, especially acrylic melamine, urethane, acrylic urethane, and melamine alkyd type paints.
(2) Description of the Prior Art
Polyamides are excellent as engineering plastics, and as such, are used in large quantities in automobiles, electric appliances, farming equipment, and construction materials. The need has arisen recently for the development of polyamides on which coatings of desired color tones can be formed. However, conventional polyamides have a poor adhesion to coatings; when coatings are formed directly on molded polyamide articles, the coating readily peels or rubs off during use of the articles. Accordingly, the coating of polyamide molded articles has heretofore been accomplished by a complicated method in which a a primer is first applied, followed by a layer of paint. This method is in itself complicated and troublesome, and moreover, gives rise to a serious practical problem when applied to the coating of exterior trim parts on automobiles and the like. Namely, when an outer metal plate of an automobile and an exterior polyamide trim part coated with paint of the same color, a delicate discrepancy in color arises, lowering the commercial value. Furthermore, the number of coating steps and the coating cost are increased.